Organoaluminum compounds containing dialuminoalkane grousp(&gt;Al--R--Al&lt;) are known. Oligomeric aluminum methylene compounds and bis(dichloroaluminum) methane have been made by reaction of aluminum metal with methylene chloride as shown in the following equation given by Lehmkuhl and Schafer, Tetrahedron Lett., No. 21, 2315 (1966): ##STR2## The authors used these compounds as co-catalysts for olefin polymerization procedures, such as those described in German Pat. No. 1,264,443.
1,2-Bis(dichloroaluminum)ethane has been prepared by reduction of aluminum chloride with potassium in the presence of ethylene according to the following equation from Kooyman et al., Tetrahedron Lett., No. 12, 24 (1959): ##STR3## They obtained the compound described above as the diethyl ether complex, Al.sub.2 Cl.sub.4 C.sub.2 H.sub.4.2Et.sub.2 O. Though the authors did not isolate the ether-free compound, they suggested that this compound was the active co-catalyst with TiCl.sub.4 in some ethylene polymerization tests which they performed. Compounds closely related to the present invention are also described in German Pat. No. 2,236,193.